Packaging method of semiconductor substrate, packaged substrate, and packaging control method

Abstract

The application provides a packaging method of a semiconductor substrate, a packaging substrate and a packaging control method. The semiconductor substrate has a first cavity structure, and the first cavity structure is communicated with the outside of the semiconductor substrate through at least one first filling hole. The packaging method comprises the following steps: S1, transferring a first container containing liquid metal and the semiconductor substrate into a sealed container; S2, reducing the pressure in the sealed container to negative pressure, and then communicating the sealed container with the outside of the sealed container, so that the liquid metal is filled into the first cavity structure through the first filling hole. Through the application, the technical problem that the liquid metal cannot be effectively filled into a small packaging substrate in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor advanced packaging technology, in particular to a packaging method of a semiconductor substrate, a packaging substrate and a packaging control method. BACKGROUND

[0002] To meet the heat dissipation requirements of chips, the industry has mentioned the concept of near-junction heat dissipation, that is, various miniaturized heat dissipation structures are embedded in the electronic chip packaging structure, and the embedded heat dissipation structure is used to force the liquid cooling working medium to approach (distance less than 100 μm) the electronic chip heat grid area to realize accurate regulation of junction temperature. According to whether the embedded liquid cooling heat dissipation technology needs external energy to drive the cooling working medium, it can be divided into two forms: active and passive. Among them, the active embedded liquid cooling needs external non-thermal physical effect power (such as mechanical force, electromagnetic force, etc.) to provide kinetic energy to drive the liquid cooling working medium to circulate in the embedded cavity; the passive embedded liquid cooling method can also realize effective inhibition of local high heat flux caused by heat accumulation in the closed cavity by using the thermal physical effect (such as thermal slip, phase change, capillary condensation, etc.) of the liquid cooling working medium. Compared with the complex external circulation pump valve system indispensable for the active embedded liquid cooling structure, only the passive embedded liquid cooling structure is integrated in the substrate, which can achieve satisfactory uniform temperature heat dissipation effect (± 5℃), and there is no need to consider the vertical interconnection of the flow path between the substrate layers in 2.5D / 3D packaging.

[0003] In highly integrated electronic chip packaging, due to space limitations, further improving the passive heat dissipation capability is challenging. To solve this problem, liquid metal is considered an ideal heat dissipation material due to its high thermal conductivity, high boiling point, low melting point, low thermal expansion coefficient, and diamagnetic properties, enabling liquid metal to maintain electronic device performance while withstanding extreme temperature changes during packaging and operation, such as gallium-based alloys. Therefore, the existing solution is to embed liquid metal in the packaging substrate. For example, the current existing embedded liquid metal tsv adapter plate filling process is mainly in a nitrogen atmosphere, using a customized silicone heating belt to heat a Teflon syringe and combining a programmable heating array tray to fill the gallium-based liquid metal above the melting point into the embedded cavity of the TSV adapter plate. As shown in FIG. 1, it is filled by injecting through the filling hole in a nitrogen-filled airtight glove box using a heated Teflon syringe. However, the process method of FIG. 2 has poor filling effect when injecting through the filling hole of the adapter plate with a very small cavity height (100 microns or even lower), the main reason being as follows: Figure 1 Figure 1 1. Since the surface tension of gallium-based liquid metal is very large, when the cavity height of the adapter plate is very low, the force of the syringe is far from enough to fill the liquid metal into the inside of the adapter plate, so that the liquid metal can only exist near the filling hole.

[0004] 1. Since the surface tension of gallium-based liquid metal is very large, when the cavity height of the adapter plate is very low, the force of the syringe is far from enough to fill the liquid metal into the inside of the adapter plate, so that the liquid metal can only exist near the filling hole. ​

[0005] 2. The Teflon syringe needle tube is relatively long, much longer than the height of the adapter plate. When the syringe needle enters the filling hole, it is easy to reach the bottom of the adapter plate, thereby blocking the filling hole and affecting the filling effect.

[0006] In summary, the existing filling process can only be used for the filling of liquid with small surface tension on the adapter plate with high cavity height. If the cavity height is very low (such as 100 microns or even lower) and the filling surface tension of the liquid metal is relatively large, the filling effect is poor, and the liquid metal can only be filled near the filling hole.

[0007] Therefore, there is an urgent need for a process that can effectively fill liquid metal into a small packaging substrate. SUMMARY

[0008] The main purpose of the present application is to provide a packaging method for a semiconductor substrate, a packaging substrate and a packaging control method to solve the technical problem that the liquid metal cannot be effectively filled into a small packaging substrate in the prior art.

[0009] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a packaging method for a semiconductor substrate is provided, the semiconductor substrate has a first cavity structure, the first cavity structure is in communication with the outside of the semiconductor substrate through at least one first filling hole, and the packaging method comprises the following steps: S1: transferring a first container containing liquid metal and a semiconductor substrate into a sealed container; S2: reducing the pressure in the sealed container to negative pressure, and then connecting the sealed container with the outside of the sealed container to fill the liquid metal into the first cavity structure through the first filling hole.

[0010] Optionally, the packaging method further comprises: placing the liquid metal in a second container; placing the second container in a heating device; and transferring the heated liquid metal into the first container containing the semiconductor substrate.

[0011] Optionally, the packaging method is carried out in a glove box, and the glove box is filled with a protective gas.

[0012] Optionally, the step of reducing the pressure in the sealed container to negative pressure comprises: using a vacuum pump to extract the gas in the sealed container to negative pressure.

[0013] Optionally, after the step of filling the liquid metal into the first cavity structure through the first filling hole, the packaging method further comprises: sealing the first filling hole with inorganic glue.

[0014] In order to achieve the above object, according to one aspect of the present application, there is provided a packaging substrate formed by a packaging method of any one of semiconductor substrates.

[0015] According to another aspect of the present application, there is provided a packaging control method applied to a potting system for packaging a semiconductor substrate, the potting system comprising a vacuum pump, the packaging control method comprising: obtaining a first potting state of liquid metal in the semiconductor substrate when the semiconductor substrate is filled with the liquid metal; and controlling the vacuum pump to perform S2 at least once when the first potting state does not satisfy a first preset relationship, until the first potting state satisfies the first preset relationship.

[0016] Optionally, the potting system further comprises a glove box and a gas tank, the glove box being in communication with the gas tank through a gas valve, and the packaging control method further comprises: obtaining a gas concentration in the glove box; and controlling the gas valve to open when the gas concentration does not satisfy a second preset relationship.

[0017] Optionally, the packaging control method further comprises: obtaining a first mass of the semiconductor substrate; and determining a volume of the liquid metal in the semiconductor substrate according to the first mass and an initial mass of the semiconductor substrate.

[0018] Optionally, the potting system further comprises an operation table, and the packaging control method further comprises: obtaining a second potting state of the liquid metal in a reference substrate before the liquid metal is filled into the semiconductor substrate, the liquid metal in the reference substrate being obtained by a preset procedure, the preset procedure comprising: transferring a first container containing the liquid metal and a target substrate into a sealed container, connecting the sealed container with the outside of the sealed container after reducing the pressure in the sealed container to a negative pressure, filling the liquid metal into a cavity structure of the target substrate through a potting hole of the target substrate, the target substrate comprising the semiconductor substrate and the reference substrate; and controlling the operation table and the vacuum pump to package the semiconductor substrate when the second potting state satisfies the first preset relationship, the operation table being used to perform the preset procedure.

[0019] The application provides a packaging method of a semiconductor substrate, the semiconductor substrate has a first cavity structure, the first cavity structure is communicated with the outside of the semiconductor substrate through at least one first filling hole, and the packaging method comprises the following steps: placing a first container containing liquid metal and the semiconductor substrate in a sealed container; reducing the pressure in the sealed container to negative pressure, and then communicating the sealed container with the outside of the sealed container, so that the liquid metal is filled into the first cavity structure through the first filling hole. According to the application, because the pressure of the atmospheric pressure area outside the sealed container is higher than the pressure in the sealed container at the moment when the sealed container in the negative pressure is communicated with the outside of the sealed container, a pressure difference is formed between the first cavity structure of the semiconductor substrate in the sealed container and the outside atmospheric pressure, at this moment, in order to balance the pressure difference between the sealed container and the outside of the sealed container, the liquid in the sealed container is forced into the first cavity structure of the semiconductor substrate by the higher atmospheric pressure. It can be understood that the driving force generated by the pressure difference is much greater than the resistance generated by the surface tension of the liquid metal, therefore, even if the surface tension of the liquid metal is large, the packaging method of the application can still make the liquid metal flow smoothly and fill the first cavity structure, and the liquid metal is not affected by the surface tension of the liquid metal, thereby solving the technical problem that the liquid metal cannot be effectively filled into the small packaging substrate in the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings, which form a part of the specification, are included to provide a further understanding of the application and are incorporated herein in conjunction with the description of the application. The embodiments of the present application, together with its advantages, can best be understood by referring to the following detailed description taken in connection with the accompanying drawings in which:

[0021] Figure 1 A filling device of a TSV adapter plate in the prior art is shown;

[0022] Figure 2 A structure schematic diagram of a silicon substrate according to an embodiment of the application is shown;

[0023] Figure 3 A structure schematic diagram of a filling system according to an embodiment of the application is shown;

[0024] Figure 4 A structure schematic diagram of a silicon glass substrate filled with 80% volume gallium according to an embodiment of the application is shown. DETAILED DESCRIPTION

[0025] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] In the following, the technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application, so that those skilled in the art can better understand the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the protection scope of the present application.

[0027] It should be noted that the terms "first", "second" and the like in the description and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented. In addition, the terms "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units does not necessarily limit to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0028] As described in the background, in highly integrated electronic chip packages, due to space limitations, further improving the passive heat dissipation capability is challenging. To solve this problem, liquid metal is considered an ideal heat dissipation material due to its high thermal conductivity, high boiling point, low melting point, low thermal expansion coefficient, and diamagnetism, etc., so that the liquid metal can maintain the performance of electronic devices while withstanding extreme temperature changes during packaging and operation, such as gallium-based alloys. Therefore, the solution proposed in the prior art is to embed the liquid metal in the packaging substrate. For example, the current existing embedded liquid metal tsv adapter plate filling process is mainly in a nitrogen atmosphere, through a customized silica gel heating belt to heat a Teflon syringe and combine with a program-controlled heating array tray, to fill the gallium-based liquid metal above the melting point into the embedded cavity of the TSV adapter plate. However, due to the high surface tension of gallium-based liquid metal, when the adapter plate cavity height is very low, the force of the syringe is far from enough to fill the liquid metal into the adapter plate, so that the liquid metal can only exist near the filling hole, and the Teflon syringe needle is relatively long, much longer than the height of the adapter plate. When the syringe needle enters the filling hole, it is easy to reach the bottom of the adapter plate, thereby blocking the filling hole and affecting the filling effect. Therefore, the above process method has poor filling effect when filling through the filling hole by using a syringe to fill the adapter plate with a narrow cavity height (100 μm or even lower). On this basis, in order to solve the technical problem that the liquid metal cannot be effectively filled into the small packaging substrate in the prior art, the present application provides a packaging method of a semiconductor substrate, a packaging substrate and a packaging control method.

[0029] According to a first aspect of this application, a method for packaging a semiconductor substrate is provided. The semiconductor substrate has a first cavity structure, and the first cavity structure communicates with the outside of the semiconductor substrate through at least one first potting hole. The packaging method includes the following steps:

[0030] S1: Transfer the first container containing the liquid metal and the aforementioned semiconductor substrate to a sealed container;

[0031] S2: After reducing the pressure in the sealed container to a negative pressure, connect the sealed container to the outside of the sealed container so that the liquid metal can be filled into the first cavity structure through the first filling hole.

[0032] Specifically, when both the liquid metal and the semiconductor substrate are placed in the first container, in order to facilitate subsequent pouring so that the liquid metal fills the first cavity structure, the liquid metal can just cover the semiconductor substrate.

[0033] Specifically, the liquid metal mentioned above can be a gallium-based liquid metal.

[0034] Specifically, such as Figure 2 As shown, the semiconductor substrate can be a silicon substrate.

[0035] For example, the method for fabricating the silicon substrate described above may include: providing a first silicon substrate and a second silicon substrate; etching the second silicon substrate to form a groove on one side surface of the second silicon substrate, wherein a plurality of silicon pillars are spaced apart in the groove; bonding one side of the first silicon substrate to the side of the second silicon substrate with the groove to form a silicon substrate, wherein the silicon substrate has a first cavity structure formed by bonding the first silicon substrate and the second silicon substrate. Furthermore, the silicon substrate may be etched to form a first potting hole in the silicon substrate, wherein the first potting hole connects the first cavity structure inside the silicon substrate and the outside of the silicon substrate.

[0036] Optionally, before bonding the first silicon substrate and the second silicon substrate, the method for fabricating the silicon substrate further includes: epitaxially growing a gallium nitride layer on one side of the first silicon substrate, and then etching the gallium nitride with KOH to obtain a patterned first silicon substrate. Next, in the step of bonding the first silicon substrate and the second silicon substrate, the side of the patterned first silicon substrate with the gallium nitride layer can be bonded to the side of the second silicon substrate with the groove, such that the gallium nitride layer is located between any two adjacent silicon pillars.

[0037] Optionally, in the step of bonding the first silicon substrate and the second silicon substrate, silicon-silicon bonding can be performed on the first silicon substrate and the second silicon substrate at a high temperature of 1000°C to form a silicon substrate with a first cavity structure.

[0038] Optionally, before the step of forming the first potting hole in the silicon substrate, a chemical mechanical polishing process can also be used to thin the semiconductor substrate after bonding.

[0039] Exemplarily, the thickness of the semiconductor substrate (silicon substrate) can be less than or equal to 100 microns. Exemplarily, the first potting hole can be a 0.6mm radius potting hole, as shown in Figure 2

[0040] In the above embodiment, when the first container containing the liquid metal and the semiconductor substrate is transferred to the sealed container, and the pressure in the sealed container is reduced to negative pressure, and then the sealed container is connected to the outside of the sealed container, at the moment when the sealed container at negative pressure is connected to the outside of the sealed container, the atmospheric pressure in the outside of the sealed container is higher than the pressure in the sealed container, thereby forming a pressure difference between the first cavity structure of the semiconductor substrate in the sealed container and the outside atmosphere. At this time, in order to balance the pressure difference between the sealed container and the outside of the sealed container, the liquid in the sealed container will be forced into the first cavity structure of the semiconductor substrate through the first potting hole of the semiconductor substrate by the higher atmospheric pressure. It can be understood that the driving force generated by the pressure difference is much greater than the resistance generated by the surface tension of the liquid metal, so even if the surface tension of the liquid metal is large, the liquid metal can still flow smoothly and fill the first cavity structure through the packaging method of the present application, without being affected by the surface tension of the liquid metal, thereby solving the technical problem that the liquid metal cannot be effectively potting into the small packaging substrate in the prior art.

[0041] In some optional embodiments, the packaging method further comprises: placing the liquid metal in a second container; placing the second container on a heating device; and transferring the heated liquid metal into the first container containing the semiconductor substrate.

[0042] Specifically, since the flowability of the liquid metal at room temperature is poor, it is not conducive to the potting of the semiconductor substrate, therefore, in order to improve the flowability of the liquid metal, the above embodiment realizes the heating of the liquid metal by placing the liquid metal in a second container and heating the second container on a heating device, thereby improving the flowability of the liquid metal.

[0043] Exemplarily, the liquid metal can be heated to 80℃.

[0044] Optionally, the material of the second container can be polystyrene, which will not deform at a heating temperature of about 100℃. It should be noted that the second container cannot be a metal container to prevent the reaction of metal and gallium.

[0045] ​In some alternative embodiments, in order to prevent the liquid metal from being oxidized and maximize the heat dissipation capacity of the liquid metal in the semiconductor substrate, the packaging method is performed in a glove box, and the glove box is filled with a protective gas.

[0046] Exemplarily, the protective gas can be nitrogen.

[0047] In some alternative embodiments, the step of reducing the pressure in the sealed container to a negative pressure comprises: extracting the gas in the sealed container to a negative pressure by using a vacuum pump.

[0048] In the above embodiments, by extracting the gas in the container by using a vacuum pump, the number of gas molecules in the sealed container can be reduced, thereby reducing the pressure.

[0049] Exemplarily, the gas in the sealed container can be extracted until the pressure in the sealed container is -0.1 Mpa.

[0050] In some alternative embodiments, in order to prevent the liquid metal from leaking, after the step of filling the liquid metal into the first cavity structure through the first filling hole, the packaging method further comprises: sealing the first filling hole by using inorganic glue.

[0051] Optionally, before the step of sealing the first filling hole by using inorganic glue, part of the protective gas can be reserved inside the first cavity structure, thereby being used for the two-phase flow movement of the critical liquid metal and the protective gas under the temperature gradient.

[0052] It is explained herein that, in order to make the semiconductor substrate have good heat dissipation capacity, after the step of filling the liquid metal into the first cavity structure through the first filling hole, the filling state of the liquid metal in the semiconductor substrate can be detected, and then the first filling hole is sealed by using the inorganic glue when the filling state reaches the expectation.

[0053] Optionally, the inorganic glue is high-temperature-resistant inorganic glue. After the first filling hole is coated with glue, it can be stored at room temperature for 16 hours, and then heated in a constant temperature box at 150°C for two hours, and then taken out and slowly cooled.

[0054] According to a second aspect of the present application, a packaged substrate is provided, which is prepared by using any one of the above semiconductor substrate packaging methods.

[0055] Specifically, the packaging substrate can be a TSV adapter plate. The preparation method of the TSV adapter plate can further include constructing a SiO2insulating layer by oxidizing a specific region, depositing a barrier layer, and filling copper metal, and then constructing a through silicon via in the center of the corresponding silicon column in the silicon-silicon bonding sheet. Subsequently, the lower surface of the silicon wafer is thinned by chemical mechanical polishing, and then the adapter plate is rewired by RDL (Redistribution layer) to construct a circuit structure, and then a filling hole is etched on the silicon substrate by DRIE. In this way, the TSV adapter plate with an embedded cavity is manufactured.

[0056] According to a third aspect of the present application, in order to make the filling rate of the liquid metal in the semiconductor substrate reach the target filling rate, a packaging control method is provided, which is applied to a filling system as shown in the figure, the filling system is used for packaging a semiconductor substrate, and the filling system includes a vacuum pump. The packaging control method includes: obtaining a first filling state of the liquid metal in the semiconductor substrate when the semiconductor substrate is filled with the liquid metal; and controlling the vacuum pump to execute step S2 at least once until the first filling state satisfies the first preset relationship when the first filling state does not satisfy the first preset relationship. Figure 3

[0057] Specifically, the first filling state of the liquid metal in the semiconductor substrate can be observed by using an X-ray instrument (such as the X-ray instrument box shown in the figure). Figure 3

[0058] In the above embodiment, the first preset relationship can be that the filling rate of the liquid metal in the semiconductor substrate is within a preset target filling rate range of the semiconductor substrate. For example, when the filling rate of the liquid metal in the semiconductor substrate is not within the preset target filling rate range, the vacuum pump can be controlled to extract the gas in the sealed container (such as the vacuum tank shown in the figure), so as to reduce the pressure in the sealed container to negative pressure, and then the sealed container is connected with the external atmospheric pressure to fill the liquid metal in the first cavity structure of the semiconductor substrate through the first filling hole; and the first filling state of the liquid metal in the semiconductor substrate is continuously obtained until the filling rate of the liquid metal in the semiconductor substrate is within the preset target filling rate range, and the above S2 is stopped. Figure 3

[0059] Figure 3 ​​​​As shown, the potting system further comprises a glove box and a gas tank (nitrogen tank), the glove box is communicated with the gas tank through a gas valve (control valve), and the potting control method further comprises: obtaining the gas concentration in the glove box; and in the case that the gas concentration does not satisfy a second preset relationship, controlling the gas valve to open until the gas concentration satisfies the second preset relationship. Optionally, the gas valve can be installed on a connecting conduit for communicating the glove box and the gas tank.

[0060] In the above embodiment, the potting of the semiconductor substrate is performed in the glove box, so as to prevent the liquid from being oxidized. The second preset relationship can be that the gas concentration in the glove box is within a preset target gas concentration range in the glove box. For example, the gas concentration in the glove box can be detected by a gas detector (such as a nitrogen concentration detector), so that in the case that the gas concentration is not within the preset target gas concentration range in the glove box, the gas valve (control valve) for communicating the glove box and the gas tank (nitrogen tank) can be controlled to open until the gas detector (nitrogen concentration detector) detects that the gas concentration in the glove box is within the preset target gas concentration range, and then the gas valve (control valve) is closed. Figure 3

[0061] Optionally, as shown, the potting system can further comprise a heating platform (or a heating device) for heating the liquid metal. Figure 3

[0062] The potting control method further comprises: obtaining a first mass of the semiconductor substrate; and determining the volume of the liquid metal in the semiconductor substrate according to the first mass and an initial mass of the semiconductor substrate.

[0063] Specifically, the initial mass of the semiconductor substrate is the mass before the liquid metal is filled. According to the difference between the first mass and the initial mass, the mass of the liquid metal filled into the first cavity structure of the semiconductor substrate can be determined, and then according to the ratio of the mass and the density of the liquid metal, the volume of the liquid metal can be determined when the density of the liquid metal is known.

[0064] Optionally, as shown, the potting system can further comprise a one-tenth-of-a-gram electronic scale, and the mass of the semiconductor substrate can be accurately measured by using the one-tenth-of-a-gram electronic scale, so as to obtain the mass of the liquid metal in the semiconductor substrate. Figure 3

[0065] In some optional embodiments, for the potting state of the liquid metal in the silicon substrate, the potting effect inside the silicon substrate can be first observed by using an X-ray instrument, and then the volume of the liquid metal in the silicon substrate can be accurately determined by the mass measurement method.

[0066] ​​​The above filling system further comprises an operation table, and before the liquid metal is filled into the semiconductor substrate, the packaging control method further comprises: obtaining a second filling state of the liquid metal in a reference substrate, the liquid metal in the reference substrate being obtained by a preset program, the preset program comprising: transferring a first container (such as the container shown in the figure) containing the liquid metal and a target substrate into a sealed container, reducing the pressure in the sealed container to negative pressure, and then connecting the sealed container with the outside of the sealed container to fill the liquid metal into the cavity structure of the target substrate through the filling hole of the target substrate, the target substrate comprising the semiconductor substrate and the reference substrate; in the case that the second filling state satisfies the first preset relationship, controlling the operation table and the vacuum pump to package the semiconductor substrate, and the operation table is used to execute the preset program. Figure 3

[0067] In the above embodiment, the reference substrate can be a silicon glass substrate, and the semiconductor substrate can be a silicon substrate. Since silicon is opaque, it is difficult to know the internal filling condition during the filling of the silicon substrate. Therefore, the silicon glass substrate is first packaged in this embodiment, one side of which is a silicon substrate with silicon columns exposed by etching, and the other side is a glass substrate. Then, the silicon and glass are bonded to form a silicon glass substrate, Figure 4 is a structural diagram of the silicon glass substrate. As can be seen, the internal silicon columns and the internal cavity state (nitrogen and liquid metal gallium) can be clearly seen through the glass substrate side. Through the filling process test of the silicon glass substrate, it can be known whether the second filling state corresponding to the silicon glass substrate satisfies the first preset relationship. It can be understood that if the second filling state corresponding to the silicon glass substrate satisfies the first preset relationship, the silicon substrate can be filled, which will make the filling effect of the silicon substrate better.

[0068] It should be noted that the above silicon glass substrate can have a second cavity structure (cavity), and the second cavity structure can be in communication with the outside of the silicon glass substrate through at least one second filling hole.

[0069] In some optional embodiments, for the filling state of the liquid metal in the silicon glass substrate, since the glass is transparent, the silicon glass substrate can be first observed by the naked eye, and then accurately weighed by a one-millionth precision electronic scale, so that the difference between the weighing and the initial mass of the silicon glass substrate can be obtained, and then the volume of the liquid metal in the silicon glass substrate can be determined according to the above difference and the density of the liquid metal.

[0070] In some optional embodiments, the liquid metal in the semiconductor substrate accounts for 80% or 60% of the first cavity structure. ​

[0071] From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects:

[0072] The technical scheme of the present application provides a packaging method of a semiconductor substrate, the semiconductor substrate has a first cavity structure, the first cavity structure is communicated with the outside of the semiconductor substrate through at least one first filling hole, and the packaging method comprises the following steps: placing a first container containing liquid metal and a semiconductor substrate in a sealed container; reducing the pressure in the sealed container to negative pressure, and then communicating the sealed container with the outside of the sealed container, so as to fill the liquid metal into the first cavity structure through the first filling hole. According to the present application, at the moment when the sealed container under negative pressure is communicated with the outside of the sealed container, the atmospheric pressure outside the sealed container is higher than the pressure in the sealed container, so that a pressure difference is formed between the first cavity structure of the semiconductor substrate in the sealed container and the outside atmosphere. At this time, in order to balance the pressure difference between the sealed container and the outside of the sealed container, the liquid in the sealed container will be forced into the first cavity structure of the semiconductor substrate by the higher atmospheric pressure. It can be understood that the driving force generated by the atmospheric pressure difference is much greater than the resistance generated by the surface tension of the liquid metal. Therefore, even if the surface tension of the liquid metal is large, the packaging method of the present application can still make the liquid metal flow smoothly and fill the first cavity structure, and will not be affected by the surface tension of the liquid metal, thereby solving the technical problem that the liquid metal cannot be effectively filled into the small packaging substrate in the prior art.

[0073] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A packaging method of a semiconductor substrate, characterized by, The semiconductor substrate has a first cavity structure, the first cavity structure is communicated with the outside of the semiconductor substrate through at least one first filling hole, and the packaging method comprises the following steps: S1: transferring a first container containing liquid metal and the semiconductor substrate into a closed container; S2: reducing the pressure in the closed container to negative pressure, and then connecting the closed container with the outside of the closed container to fill the liquid metal into the first cavity structure through the first filling hole.

2. The packaging method according to claim 1, characterized in that, The packaging method further comprises: placing the liquid metal in a second container; placing the second container into a heating device; transferring the heated liquid metal into the first container containing the semiconductor substrate.

3. The packaging method according to claim 1 or 2, characterized in that, The packaging method is carried out in a glove box, and the glove box is filled with a protective gas.

4. The packaging method according to claim 1 or 2, characterized by, The step of reducing the pressure in the closed container to negative pressure comprises: extracting the gas in the closed container to negative pressure by using a vacuum pump.

5. The packaging method according to claim 1 or 2, characterized by, After the step of filling the liquid metal into the first cavity structure through the first filling hole, the packaging method further comprises: sealing the first filling hole by using inorganic glue.

6. A package substrate, characterized by, The semiconductor substrate is prepared by using the packaging method according to any one of claims 1 to 5.

7. A method of package control, characterized by, The packaging control method is applied to a filling system for packaging a semiconductor substrate, the filling system comprises a vacuum pump, and the packaging control method comprises: obtaining a first filling state of liquid metal in the semiconductor substrate when the semiconductor substrate is filled with the liquid metal; controlling the vacuum pump to execute the S2 of claim 1 at least once until the first filling state satisfies a first preset relationship in the case that the first filling state does not satisfy the first preset relationship; The filling system further comprises an operation table, and the packaging control method further comprises: obtaining a second filling state of liquid metal in a reference substrate, the liquid metal in the reference substrate is packaged by a preset program, and the preset program comprises: transferring a first container containing liquid metal and a target substrate into a closed container, reducing the pressure in the closed container to negative pressure, and then connecting the closed container with the outside of the closed container to fill the liquid metal into a cavity structure of the target substrate through a filling hole of the target substrate, the target substrate comprising the semiconductor substrate and the reference substrate; controlling the operation table and the vacuum pump to package the semiconductor substrate in the case that the second filling state satisfies the first preset relationship, and the operation table is used to execute the preset program.

8. The package control method according to claim 7, wherein The filling system further comprises a glove box and a gas storage tank, the glove box is communicated with the gas storage tank through a gas valve, and the packaging control method further comprises: obtaining the gas concentration in the glove box; controlling the gas valve to open in the case that the gas concentration does not satisfy a second preset relationship.

9. The package control method according to claim 8, wherein The packaging control method further comprises: obtaining a first mass of the semiconductor substrate; Based on the first quality and an initial quality of the semiconductor substrate, a volume of the liquid metal in the semiconductor substrate is determined.

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